1. Technical Field
The present invention relates to a power inductor and a manufacturing method thereof, and more particularly, to a coil pattern structure included in the power inductor.
2. Description of the Related Art
As information technologies advance, devices are getting smaller and thinner, and, accordingly, demands for smaller and thinner elements are also increasing. In accordance with the above trend, a power inductor, which is a type of surface mounted device, is developed to have a thin film structure.
FIG. 1 is a longitudinal cross-sectional view of a typical thin film power inductor, and FIGS. 2A and 2B are photographs showing a transverse cross-sectional view and a longitudinal cross-sectional view of a typical thin film power inductor.
Referring to FIG. 1, the typical thin film power inductor 1 is configured so that an electrode 2 having metal coil patterns therein is surrounded by an insulator 3 and the vicinity is filled with metal-polymer mixture 4 so as to facilitate magnetic flux flow. The electrode 2 having metal coil patterns therein is connected to an external electrode 5.
FIG. 2A shows a longitudinal cross-sectional surface of a typical thin film power inductor, and FIG. 2B shows a transverse cross-sectional surface of the typical thin film power inductor. Referring to FIGS. 2A and 2B, generally when forming inner coils 2, the aspect ratios (=plating height/plating width) at the innermost side and the outermost side are lower than those of intermediate coil patterns because the progressing direction at the innermost side and the outermost side are not defined.
Patent Document 1 discloses a method for forming conductor patterns including stacking a first conductive layer on a magnetic head, bonding a resist pattern, performing electrolyte plating to form a conductive pattern in an opening, and delaminating the resist, such that conductor patterns have the same aspect ratios. However, the method is related to the first electrolyte plating, and still has a problem with the second electrolyte plating in that the progressing direction of plating at the innermost side and the outermost side is not defined.